He started working as an usher at the Palace Theatre on Broadway, where he discovered vaudeville. There he began to develop his sense for gags and timing (rhythm and speed of a scene or action in animation). Between 1913 and 1914 he began working as a film editor for Pathé Exchange.
In 1921 he set up the Fleischer Studios with his older brother, Max Fleischer. This animation studio produced characters such as Popeye and Betty Boop. The Fleischer brothers first made Out of the Inkwell, a series of animated films starring their character Koko the Clown. From 1914 to 1916 they produced three short films to demonstrate the workings of their invention, the rotoscope: a device for animating by tracing live-action stills to give cartoons more realistic movement.
His best-known works are Gulliver's Travels (1939), Mr. Bug Goes to Town (1941) and Imagination (1943), for which he won an Oscar.
